New interactive communication technologies continue to expand in modern society. Children and adolescents are frequently among the earliest adopters of new technologies. Communication via Short Message Service (SMS) "text messaging" is one example. This application proposes to develop computer-automated methods for interactively assessing clinical states in children and adolescents using dynamically branching SMS "text" messaging. Assessment of depression will be used as a template for the proposed research. Study aims are to (1) evaluate the technical feasibility of a computer-automated interactive SMS messaging system, (2) assess acceptance of the technology among depressed children and adolescents, and (3) collect reliability and validity data on a version of the Quick Inventory of Depressive Symptomatology specifically designed for use by adolescents and delivered by SMS (QIDS-A-SMS). Long-term objectives for the development of an interactive SMS technology are to provide clinically valid, widely available, internationally accessible, easily used, and user- acceptable tools for obtaining patient reported outcomes across a wide range of conditions in pediatric patient populations. If successful, the research proposed by this application will support use of the QIDS-A-SMS as a valid treatment outcome measure in pediatric antidepressant clinical trials. Twenty-five outpatients, 8-17 years old, diagnosed with major depression will be recruited from the NIH-sponsored "Pediatric MDD: Sequential Treatment with Fluoxetine and Relapse Prevention CBT" (MH039188;Dr. Graham Emslie, PI). During office visits at baseline and at the end of 6 weeks of treatment with fluoxetine, study participants will use cell phones to complete interactive QIDS-A-SMS assessments via "text replies" to a series of dynamically branching, computer-automated SMS messages. User feedback regarding the assessment experience will be collected. Independent evaluators at the University of Texas - Southwestern Medical School will also assess depression severity using the Child Depression Rating Scale-Revised (CDRS-R) for comparison with the QIDS-A-SMS data. Technical measures of system performance such at time to complete the assessments and error frequencies, user acceptance feedback, and psychometric reliability and validity of the QIDS-A-SMS will be analyzed. PUBLIC HEALTH RELEVANCE: Modern technologies, such as "text messaging" via cellular telephone, are attractive to adolescents and may provide new opportunities to provide behavioral and mental health interventions. The technology may also be helpful for assessing the impact of such interventions in pediatric populations. Major depression is a disabling condition that often begins between the ages of 15-19 years, disrupting development, impairing functioning, and increasing risk for substance abuse, suicide, and adulthood depression. Recent concerns about an increased risk of suicide in adolescents being treated with antidepressants have focused public attention on the need for closer monitoring of adolescent signs and symptoms of depression.